096
FXUS64 KLUB 031742
AFDLUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1142 AM CST TUE MAR 3 2015
.AVIATION...
FLIGHT CONDITIONS HAVE RAPIDLY IMPROVED LATE THIS MORNING AND THE
CURRENT EXPECTATION IS THAT CATEGORIES WILL REMAIN MOSTLY VFR
THROUGH THIS EVENING. WE WILL PROBABLY SEE SOME RAIN SHOWERS MOVE
ACROSS THE REGION LATE THIS AFTERNOON THOUGH THE PROBABILITY OF
AFFECTING THE TERMINAL REMAINS TOO LOW FOR EXPLICIT MENTION AT
THIS TIME. INTO TONIGHT...A SHARP COLD FRONT WILL MOVE IN
AFFECTING KCDS AROUND MIDNIGHT AND SWEEPING SE THROUGH SUNRISE.
BEHIND THIS FRONT...LOW IFR CONDITIONS WITH HIGH ICING POTENTIAL
ALONG WITH MIXED PRECIPITATION AT THE SURFACE IS ANTICIPATED.
MORNING CARGO/MEDICAL FLIGHTS VERY WELL COULD BE IMPACTED WITH
CONDITIONS WORSENING THROUGH 18Z WED.
&&
PREV DISCUSSION... /ISSUED 420 AM CST TUE MAR 3 2015/
SHORT TERM...
A COOL AND MOIST BOUNDARY LAYER IS IN PLACE ACROSS THE REGION BUT
FOR THE FIRST TIME IN SEVERAL DAYS TEMPERATURES ARE ABOVE FREEZING.
AREAS THAT STILL HAVE SOME SNOW ON THE GROUND HAVE HAD BRIEF PERIODS
OF DENSE FOG AS TEMPERATURE AND DEWPOINT SPREAD IS VERY CLOSE OR
ZERO IN SOME CASES. ALOFT...THE CORE OF THE SUBTROPICAL JET REMAINS
WEST OF THE REGION WITH THE EASTERN EDGE STARTING TO PUSH OVER US.
THIS HAS ALLOWED SUBTROPICAL MOISTURE TO ALSO PUSH OVER THE REGION
AS SHOWN BY WATER VAPOR SATELLITE IMAGERY...AND THE IMAGERY ALSO
SHOWS A CLOSED LOW SPINNING OFF THE SOUTHWESTERN CALIFORNIA COAST.
ALL OF THESE FEATURES COMBINED ARE MAKING FOR A COMPLICATED FORECAST
FOR TODAY INTO TONIGHT.
FIRST ISSUE WILL BE WHEN OR IF WE WILL SEE SKIES CLEAR OUT.
REGIONAL SURFACE HAND ANALYSIS SHOWS NO DRY AIR TO THE SOUTH OR
SOUTHWEST OF THE REGION WITH DEWPOINTS INCREASING INTO THE MID 40S
ACROSS THE CONCHO VALLEY AND RIO GRANDE RIVER VALLEY INTO SOUTHERN
NEW MEXICO. WITH SURFACE WIND REMAINING OUT OF THE SOUTH TO
SOUTHWEST...A GRADUAL INCREASE IN DEWPOINTS IS EXPECTED AS THIS
AIRMASS IS ADVECTED INTO THE FORECAST AREA. JUST ABOVE THE
SURFACE...A LAYER OF DRY AIR IS IN PLACE AROUND 700 HPA. AS THE
CLOSED LOW MOVES TOWARDS THE REGION THROUGH THE AFTERNOON AND
WEAKENS INTO AN OPEN WAVE...MID-LEVEL MOISTURE WILL INCREASE WHICH
DOES NOT FAVOR CLOUD COVER GOING AWAY EITHER. HOWEVER AS THE TROF
APPROACHES...THE JET AXIS WILL SHIFT EAST AND SUBSIDENCE ON THE BACK
SIDE OF THE JET MAY ALLOW SOME CLEARING TO TAKE PLACE LATE IN THE
DAY. HIGH TEMPERATURE FORECAST WILL BE A CONTEST BETWEEN SKIES
STAYING MOSTLY CLOUDY TO CLOUDY FOR THE COOL SIDE VERSUS WARM
ADVECTION THROUGH THE DAY OFFSETTING THE CLOUD COVER FOR THE WARMER
SIDE. DID COOL TEMPERATURES ACROSS THE ROLLING PLAINS AS MODELS
WERE GOING NEAR 70 DEGREES BUT KEPT HIGHS ON THE CAPROCK CLOSE TO 60.
NEXT ISSUE THROUGH THE DAY IS PRECIPITATION. SHORTWAVES EMBEDDED IN
THE SUBTROPICAL FLOW WILL BE MOVING ACROSS THE AREA THROUGH THE DAY
PROVIDING PERIODS OF WEAK TO MODERATE LIFT. MODELS SHOW SHOWERS
DEVELOPING THROUGH THIS AFTERNOON WITH MORE ROBUST AMOUNTS ACROSS
THE CENTRAL PART OF THE FORECAST AREA. HARD TO SAY WHETHER THIS
WILL HAPPEN AS LACK OF INSOLATION WILL HAMPER ANY KIND OF SURFACE-
BASED INSTABILITY AND SOUNDING PROFILES SHOW VERY MEAGER TO NON-
EXISTENT AMOUNTS OF INSTABILITY ALOFT. DID INCREASE POPS SOME FOR
THIS AFTERNOON BUT STILL MAINTAINED ONLY ISOLATED SHOWERS FOR NOW IN
THE WEATHER GRIDS. EXPECT ANY PRECIPITATION TO REMAIN FAIRLY LIGHT
WITH ONLY A FEW HUNDREDTHS OF ACCUMULATION...BUT WILL HAVE TO WATCH
AND SEE HOW THINGS UNFOLD THROUGH THE DAY AS UNCERTAINTY IS HIGH AS
TO HOW POPS WILL DEVELOP.
PRECIPITATION CHANCES WILL CONTINUE TO INCREASE TONIGHT INTO
WEDNESDAY MORNING AS THE MAIN TROUGH MOVES TOWARDS THE REGION AND AS
A STRONG COLD FRONT STARTS TO PUSH INTO THE FORECAST AREA. MODELS
HAVE SLOWED DOWN THE PROGRESSION OF THE FRONT AND DO NOT HAVE IT
THROUGH THE ENTIRETY OF THE FORECAST AREA UNTIL LATE IN THE DAY
WEDNESDAY. THIS IS SIGNIFICANT BECAUSE LOW TEMPERATURES WERE BROUGHT
UP ABOVE FREEZING FOR ALL BUT THE NORTHERN ROW OF COUNTIES.
PRECIPITATION SHOULD STAY LIQUID SOUTH OF A MULESHOE...TULIA...
FLOYDADA...TO PADUCAH LINE AS TEMPERATURES SOUTH OF THAT LINE WILL
BE IN THE UPPER 30S TO LOW 40S BY SUNRISE WEDNESDAY. NORTH OF THAT
LINE...WE WILL SEE A TRANSITION FROM RAIN...TO RAIN AND SLEET...THEN
ALL SLEET...THEN FINALLY ALL SNOW BY 6 AM TOMORROW AS A FIRST GUESS.
STILL UNCERTAIN AS TO HOW FAST THE TRANSITION WILL TAKE AS MODELS
ARE STRUGGLING WITH HOW QUICKLY TO COOL THE ATMOSPHERIC COLUMN WITH
THE INITIAL SURGE OF COLD AIR INTO THE AREA. MODELS HAVE HAD A MUCH
FASTER PROGRESSION AND STRONG COLD AIR ADVECTION THE PAST SEVERAL
RUNS SO AGAIN...THERE IS QUITE A BIT OF UNCERTAINTY ON HOW THINGS
WILL DEVELOP TOMORROW MORNING.
JORDAN
LONG TERM...
THE STORY OF THE NEVER ENDING WINTER CONTINUES AS MORE WINTRY PRECIP
IS EXPECTED WED INTO THURS. A STRONG ARCTIC FRONT WILL BE IN THE
PROCESS OF MOVING THROUGH THE FA BY SUNRISE WED. THAT MEANS BREAK
OUT THE THERMOS OF COFFEE AND HOT COCOA BECAUSE THE TEMPERATURE YOU
FEEL WHEN YOU STEP OUTSIDE THAT MORNING WILL BE THE WARMEST IT WILL
BE ALL DAY. STRONG CAA IN ADDITION TO THICK CLOUD COVER WILL ALLOW
TEMPS TO DROP STEADILY DURING THE DAY. THE WARMEST AREAS WILL BE
JUST AHEAD OF THE FRONT WHERE COMPRESSIONAL HEATING WILL KEEP
MORNING TEMPS IN THE LOW 40S. THOUGH GETTING THE HIGH TEMP IS A BIT
OF A CHALLENGE ITSELF...THE BIGGER CHALLENGE IS FORECASTING THE P-
TYPE THROUGH MID DAY. SOUNDING PROFILES SUPPORT MOSTLY FROZEN
PRECIP...SNOW AND SLEET...FOR THE NORTHERN HALF OF THE FA AFTER 6AM
AS COLD AIR ALOFT WORKS INTO THE AREA. THE SOUTHERN HALF OF THE FA
SHOULD SEE RAIN BEGINNING TO MIX WITH SLEET AND SNOW THROUGH NOON.
AFTER NOON SURFACE TEMPS SHOULD BE BELOW FREEZING ACROSS THE FA
THUS ELIMINATING THE CHANCE FOR RAIN. THE QUESTION THEN REMAINS OF
HOW LONG WILL SLEET MIX IN WITH SNOW BEFORE PRECIP IS ALL SNOW.
ALL SNOW IS EXPECTED ACROSS THE NORTHERN HALF OF THE FA...HOWEVER
MODEL SOUNDINGS DIFFER ON WHEN THE ELEVATED WARM NOSE WILL ERODE
ACROSS THE SOUTHERN HALF OF THE FA WITH THE GFS COOLING FASTER
THAN THE NAM. THE TIMING OF THE TRANSITION TO ALL SNOW WILL EFFECT
THE AMOUNT OF SNOW ACCUMULATION. FOR NOW THE FORECAST WILL REFLECT
A CHANGE TO ALL SNOW BY 3PM. CURRENT THINKING WITH SNOWFALL
AMOUNTS IS 1-2 INCHES SHOULD BE THE AVERAGE ACROSS THE FA. THE
MAIN LIFTING MECHANISM WILL BE FRONTOGENETIC FORCING.
MODELS...HOWEVER...ARE HINTING AT ENERGY FROM A SHORTWAVE MOVING
ACROSS THE REGION WHICH WOULD HELP DEVELOP BANDING LATER WED
EVENING. THIS COULD ALLOW FOR LOCALLY HIGHER SNOWFALL AMOUNTS.
THIS WOULD SUPPORT WPC ACCUMULATION GUIDANCE SHOWING THAT THE
HIGHER SIDE OF POSSIBLE SNOWFALL...THE 90TH PERCENTILE...IS IN THE
4-6 INCH RANGE. FOR NOW FORECAST AMOUNTS WILL STAY 1-2 INCHES BUT
WILL BE ADJUSTED AS NEEDED.
SNOW SHOULD BEGIN TO WIND DOWN OVERNIGHT WED INTO EARLY THURS
MORNING AS DRIER AIR FILTERS IN TO THE REGION FROM THE WEST. SURFACE
FLOW WILL BEGIN TO VEER TO THE SOUTH IN RESPONSE TO A DEVELOPING LEETROF WHICH WILL HELP TO WARM TEMPS INTO THE MID30S/LOW 40S THURS.
SOUTHERLY TO SOUTHWESTERLY FLOW WILL PERSIST THROUGH SATURDAY
MORNING WHEN A WEAK AND DRY FRONT IS PROGGED TO PUSH INTO THE
REGION. THIS SHOULD HAVE NO REAL AFFECT ON TEMPS FOR SATURDAY WITH
HIGHS PUSHING CLOSE TO THE 60 DEGREE MARK. A WARMING TREND WILL
CONTINUE INTO NEXT WEEK AS SURFACE FLOW BECOMES SOUTHERLY AGAIN ON
SUNDAY HELPING WARM TEMPS INTO THE 60S. DRY NORTHWESTERLY FLOW ALOFT
WILL ALLOW THE SUN...WHO HAS BEEN IN HIDING FOR SOME TIME...TO COME
OUT.
ALDRICH
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 59 28 28 11 / 20 30 50 20
TULIA 62 27 27 13 / 20 30 70 20
PLAINVIEW 61 32 32 13 / 30 30 70 20
LEVELLAND 62 37 37 15 / 30 30 50 30
LUBBOCK 62 35 35 14 / 30 30 60 30
DENVER CITY 61 42 42 18 / 30 30 50 30
BROWNFIELD 62 41 41 17 / 30 30 60 30
CHILDRESS 62 29 29 15 / 30 40 70 20
SPUR 65 35 35 19 / 10 40 60 30
ASPERMONT 66 40 40 22 / 10 50 60 30
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/26